March 19, 2013

A United Launch Alliance Atlas V 401 Rocket successfully delivered the SBIRS GEO2 Satellite to Geostationary Transfer Orbit on Tuesday after a flawless 43-minute ascent mission. The Atlas V blasted off from Space Launch Complex 41 at Cape Canaveral Air Force Station, Florida, at 21:21 UTC to begin its flight. SBIRS GEO2 was released at 22:04 UTC to start its 12-year mission at a classified location in Geostationary Orbit later this year.Launch Recap Launch Day Operations began 7 hours and 30 minutes ahead of the opening of Tuesday's Launch Window. Launch Controllers reported to console inside the Atlas Space Flight Operations Center and engineers began final preparations at the launch pad. Tuesday's countdown made use of the extended T-4-Minute built-in hold with a duration of 25 minutes, in addition to the standard 30-minute hold at T-2 hours. At L-7:15, the Atlas V launch vehicle was powered up to begin final checkouts ahead of propellant loading to make sure the vehicle was properly configured for subsequent countdown and flight operations. In the early portion of the countdown, teams cleared the Vehicle Integration Facility, performed Launch Pad Close-Outs and started to set up road blocks in preparation for Blast Danger Area evacuation. Atlas V went through Flight Termination System Testing at that time and electrical verifications were completed. Once work at the Launch Complex was complete and the pad as well as the vehicle integration facility were closed out for launch, engineers departed the launch complex and cleared the Blast Danger Area to set the stage for the complex fueling process.

Photo: United Launch Alliance

Also, the Launch Hazard Area became active and Air Force controllers started to monitor the Eastern Range from the Morrell Operations Center.

As clocks continued to tick down, the Atlas V launcher was put through S- and C-Band communication system tests. At L-3:55, Nitrogen Purge Flow was initiated and the launch team received a weather briefing.

Meteorologists had issued a 70% chance of favorable conditions during the 40-minute launch window. Primary concerns were violations of the Cumulus Cloud Rule as a cold front was pushing in from the north bringing moisture that was sufficient for isolated showers. Meteorologists of the 45th Weather Squadron continued to have a close eye on the situation as the countdown continued.

When clocks were holding at T-2 hours, the launch team went through final preparations for propellant loading before teams were polled for a GO/No GO for taking. All Stations were GO and clocks starting ticking at 18:56 UTC and propellant loading operations picked up immediately.

Only cryogenic propellants had to be loaded as part of the countdown because first stage Rocket Propellant-1 Loading was completed after rollout on Monday. A total of 94,600 liters of highly refined Kerosene were filled into the fuel tank of the Common Core Booster. RP-1 loading can be completed during the final launch countdown, but generally for Atlas launches, it is completed as part of L-1 Day operations.

Photo: United Launch Alliance

Photo: United Launch Alliance

Cryogenic tanking began with the chilldown of Ground Support Equipment and Propellant Transfer Lines before the tanks of the launcher were conditioned for fueling as well.

The Centaur Liquid Oxygen System started its Chilldown Sequence at L-2:21 and the –183-degree Celsius oxidizer started flowing inside Centaur’s tank 10 minutes later. A total of 15,700 liters of LOX were loaded into Centaur. As part of Cryogenic Tanking, fueling starts in Slow Fill mode until the initial portion of the tank has been filled. At that point, Fast Fill starts and continues until tanks reach the 95% level for LOX and 97% for Hydrogen. The final part of propellant loading is completed as part of Topping. Centaur LOX loading entered Topping at L-1:45 and flight level at L-1:39.

The large Common Core Booster that stands 32.46 meters tall with a diameter of 3.81m, began its tanking sequence with LOX systems Chilldown. CCB LOX Loading began at L-1:59 and went through its nominal sequences before entering Topping 54 minutes later. In total, the CCB was loaded with 185,500 liters of LOX. No problems were encountered during CCB Loading and the prescribed cycle tests of the Propellant fill&Drain Valves was completed as planned.

The final tank to begin propellant loading was the Liquid Hydrogen Tank of the Centaur Upper Stage. At L-1:49, the LH2 System was pressurized to chilldown level followed by by the initiation of Transfer Lines Chilldown. At L-1:25, the -253-degree Celsius LH2 fuel started to flow inside the Tank that passed 97% at L-66 minutes and was filled with 48,100 liters of LH2. At liftoff, the Atlas V first stage holds 284,089 Kilograms of propellants while the Centaur contains 20,830kg of cryogenics.

With Propellant Loading completed as planned, the countdown entered a relatively quiet period while the launch team was watching over all systems of the vehicle. The pneumatics and hydraulic systems were pressurized and the RD-180 engine of the first stage and Centaur's RL-10 engine were put through a steering profile test.

Preparations for the Automated Countdown Sequence picked up again at L-50 minutes with electrical tests and another round of Open Loop Testing of the Flight Termination System that has to be satisfactory in order to give the launcher a clearance for liftoff. The FTS can be used to destroy the vehicle in case of any major anomalies during ascent. The flight computers were commanded to dump any history data and were provided a refined version of the ascent software based on the latest upper level wind models and the software load was verified by the launch team.

The RD-180 fuel fill sequence was completed just before the countdown entered the T-4-Minute built-in hold. During the 25-minute hold, the launch team executed the final checkouts and reconfigurations of the launcher and the satellite team transitioned the payload to its final launch configuration. SBIRS GEO2 was switched to internal power to get ready for its ride into orbit.

Also, the launch team was given one final weather briefing. Meteorologists were seeing GREEN observed conditions with no launch criteria being violated and with forecast conditions also being GO. The launch team was polled for a GO/No GO for launch.

All stations reported GO to resume the countdown at 21:17 UTC or liftoff four minutes later.

When resuming at the T-4-Minute mark, the countdown entered its highly choreographed automated sequence during which final reconfigurations are made to the launcher to transition the vehicle into its final launch configuration.

At T-3:55, the ground and launch vehicle pyrotechnics were enabled and at T-3 minutes, the first stage terminated LOX topping and was secured before starting to pressurize to flight level. The RP-1 tank was pressurized as well. At T-2:45, the Flight Termination System switched to battery power and 47 seconds later, the rest of the vehicle was transferred to internal power as well. 105 seconds ahead of T-0, the LOX and LH2 tanks of the second stage were secured and began pressurization to flight level.

The terminal countdown sequence of the Flight Termination System started at T-1:20 and the Launch Control System was enabled as well. All tanks were stable at flight pressure and no problems were revealed during the final status check.

The RD-180 engine of the first stage soared to life at T-2.7 seconds and started to throttle up to liftoff thrust of 390,250 Kilograms. Computers were monitoring the massive engine to ensure it reaches operational conditions before committing the vehicle to flight.

Engine start was nominal and the 58-meter Atlas V was allowed to blast off. Liftoff was at precisely 21:21:00.219 UTC and the 335,000-Kilogram launcher slowly climbed towards the scattered cloud cover at the Space Coast. After a short vertical ascent, Atlas V pitched over and started its roll maneuver to align itself with its precisely calculated ascent trajectory, departing the space coast at a launch azimuth of 98.8 degrees. When the roll maneuver was complete, the vehicle transitioned to closed loop guidance on its way uphill.

The vehicle crossed Mach 1 at T+1:21 and encountered maximum dynamic pressure at T+1:31 as the first stage continued to perform as planned on its way uphill. Burning through 284,00kg of propellants, the first stage continued powered ascent until T+4:03. Six seconds after shutting down, the Common Core Booster was separated and eight separation rockets on the CCB were fired to move the spent stage away from the Centaur Upper Stage.

Centaur ignited its RL-10 engine at T+4:19 to start a 11-minute 2-second burn to propel the stack into an elliptical parking orbit. Eight seconds after second stage ignition, the protective payload fairing was jettisoned, exposing the SBIRS GEO2 satellite when the launcher had left the dense atmosphere and aerodynamic forces could no longer harm the satellite.

Centaur continued to burn its engine providing 99.2-Kilonewtons of thrust until T+15:21. The burn was nominal and the vehicle had achieved its elliptical parking orbit of 175.4 by 1,058.9 Kilometers at an inclination of 26.8 degrees.

Once propellant settling was complete, the stack entered a 9-minute coast phase to allow the vehicle to gain altitude for the second burn to raise the apogee of the orbit and put a few more Kilometers on the perigee. The Hydrazine attitude control system of Centaur was used throughout the coast to provide vehicle control.

At T+24:07, Centaur ignited its engine again to perform its second burn which was 3 minutes and 55 seconds in duration. The vehicle performed as expected and delivered the stack into a 183.5 by 35,780.5-Kilometer orbit at an inclination of 22.2 degrees (Target: 185.2 by 35,785.8 Kilometers, 22.19°). With the successful completion of the powered ascent phase, spacecraft separation was next.

Image: ULA Live Webcast

Image: ULA Live Webcast

Image: ULA Live Webcast

The Common Core Booster and the two Fairing Halves as seen from Centaur

The vehicle entered another coast phase during which it maneuvered to the correct orientation for spacecraft separation.

At T+43:13 - 22:04 UTC, SIRS GEO2 was released and sent on its way to start a 12-year mission to serve from a classified location in Geostationary Orbit.

The Centaur Upper Stage completed separation maneuvers and the nominal Contamination and Collision Avoidance Maneuver to complete it mission which was another success for United Launch Alliance.

This flight marked the 37th launch of the Atlas V and the 619th launch of the overall Atlas program that started back in 1957. It was the 17th Atlas V to fly in the 401 configuration which currently is the most flown-launch vehicle of the year after orbiting NASA's TDRS-K and LDCM Satellites in January and February. This mission was the third of seven planned Atlas flights in 2013.

For SBIRS GEO2, a busy start to its mission in orbit is on tap. The vehicle will be maneuvered to Geostationary Orbit in the next 9 days, making 6 burns of its Leros Main Engine. Once in Geostationary Drift Orbit, the vehicle will start to deploy its appendages including two solar arrays, a light shade for the two instruments and gimbaled spot-beam communication antennas. GEO2 will undergo an extensive testing campaign before entering service in a classified location in Geostationary Orbit. It is expected that GEO2 will begin nominal operations before GEO1 that was launched back in May 2011.

GEO1 completed more than a year of extended post-launch tests before entering operational testing in November 2012, but a problem with the vehicle's communication system delayed the start of nominal operations.

About SBIRS

The Pentagon considers SBIRS one of the United States' highest priority space programs, designed to provide uninterrupted, global infrared surveillance capabilities in support of national security. SBIRS is the follow-on program to the Defense Support Program, DSP, that provided early warning for Intercontinental Ballistic Missile launches for over 30 years beginning in 1970. The advanced SBIRS sensors provide greater flexibility and sensitivity with short-wave and expanded mid-wave infrared signal detection capabilities. These enhanced capabilities allow an improved prediction accuracy to support missile warning, missile defense and battlespace characterization. SBIRS data is used to detect missile launches in real time, compute the trajectory of missiles and possible impact points, and provide targeting data to missile defense systems. The SBIRS project will consist of four satellites in Geosynchronous Orbit and two sensor packages hosted on two spacecraft in Highly Elliptical Orbits. The two HEO sensors have already been launched as part of two classified National Reconnaissance Office spacecraft in 2006 and 2008. The first SBIRS GEO satellite was delivered to orbit by an Atlas V rocket on May 7, 2011. In addition to the orbital segment, SBIRS features a ground segment consisting of the Mission Control Station at Buckley Air Force Base, Aurora, Colorado, and the Mission Control Station Backup at Shriver Air Force Base, Colorado Springs. Joint Tactical Ground Stations provide mobile downlink stations for SBIRS data.

Image: Lockheed Martin

SBIRS GEO 2 was built by Lockheed Martin with Northrop Grumman being a major subcontractor. The satellite is based on Lockheed's A2100M platform featuring two power-generating solar arrays and a three-axis stabilization system. The spacecraft is equipped with a propulsion system centered around the Leros-1C main engine.

Image: Lockheed Martin

The LEROS-1C Liquid Apogee Engine uses Hydrazine and Nitrogen Tetroxide as propellants. Leros 1C has a dry mass of 4.26 kilograms and provides 460 Newtons of thrust. It features a Columbium Chamber and delivers a specific impulse in excess of 325 seconds. Leros engines are flown on geostationary satellites and interplanetary spacecraft.

SBIRS GEO 2 is equipped with two infrared sensors, one scanning sensor and one staring sensor. The scanning sensor provides a shorter visit time over its full field of view than previous sensors used on DSP satellites. The staring sensor will be used for step-stare or dedicated stare operations over smaller areas of special interest. Sensor pointing is accomplished with pointing mirrors within the telescopes of the satellite.

The satellite has a liftoff weight of about 4,500 Kilograms.

Photo: Lockheed Martin

Photo: Lockheed Martin

Photo: United Launch Alliance

Atlas V & SBIRS GEO2 rolled to Launch Pad for Liftoff on Tuesday

March 18, 2013

Photo: United Launch Alliance

A United Launch Alliance Atlas V 401 rocket has been rolled from the Vehicle Integration Facility to the launch pad of Space Launch Complex 41 at Cape Canaveral Air Force Station. Rollout came one day ahead of the planned liftoff of the Atlas V to deliver the SBIRS-2 GEO2 Satellite to Geosynchronous Transfer Orbit. Launch is planned during a 40-minute launch window opening at 21:21 UTC on Tuesday. Monday's Rollout began at about 14:00 UTC and the 58-meter, 335,000-Kilogram launch vehicle slowly made its way to the pad atop its Mobile Launch Platform. Two trackmobiles were used to transport the platform. The trip took about 40 minutes and the Launch Platform was secured in place once the move was complete. With Atlas V at the pad, a busy day of launch preparations is on tap for teams that will put electrical connections in place and hook up propellant and communication lines. Later, the trackmobiles are removed and pad close-outs start to set the stage for countdown operations on Tuesday. Also ahead of the countdown, the Common Core Booster of the Atlas V is loaded with Rocket Propellant 1, highly refined Kerosene. A total of 94,600 liters of RP-1 are loaded into the vehicle. Countdown operations will begin 7 hours before launch with Launch Vehicle Activation. Subsequently, initial checks of the Atlas Launcher will be made and the Launch Area will be cleared of all personnel. At T-2 Hours, the cryogenic tanking process will start as the first stage is filled with Liquid Oxygen and the second stage is loaded with Liquid Hydrogen and Liquid Oxygen – going through a complex tanking procedure involving slow and fast propellant fill followed by topping and replenish. While the countdown continues, final systems checks will be performed by the Launch Team.

Final Flight Software will be loaded into the flight computers aboard the Atlas and countdown clocks will stop at the T-4-Minute Mark to give teams a chance to address any open issues and conduct the final GO/No GO Polls setting the stage for Launch.

As clocks start ticking down from T-4 Minutes, final vehicle configurations such as propellant tank pressurization and transfer to internal power will be made as part of the Automated Sequence to place the vehicle in its launch configuration. Liftoff is planned to occur at 21:21 UTC, the opening of a 40-minute launch window. Visit our Atlas V Countdown Overview for a detailed countdown timeline.

After blasting off from SLC-41 being powered by the single RD-180 engine of the first stage, the Atlas V will pitch-over and depart Florida's space coast en-route to its parking orbit. The first stage shuts down 4 minutes and 3 seconds into the flight and separates from the Centaur Upper Stage to enable it to start its first burn that is just over 11 minutes in duration. Once achieving its parking orbit, the vehicle begins a short cost phase before re-starting the RL-10 engine of the Centaur Stage at T+24 minutes. The second burn is nearly 4 minutes long and places the vehicle in a highly elliptical Geosynchronous Transfer Orbit. Spacecraft separation occurs at T+43:13.

The launch weather forecast has not changed and meteorologists are still issuing a 70% chance of favorable conditions during Tuesday's launch window with primary concerns being violations of the Cumulus Cloud Rule. In the event of a 24-hour delay, chances for favorable weather drop to 60%.

Atlas V passes Launch Readiness Review for Liftoff next Week

March 15, 2013

The next Atlas V to launch from Cape Canaveral Air force Station has passed its Launch Readiness Review allowing teams to press into final launch preparations leading to liftoff from Space Launch Complex 41 at 21:21 UTC on Tuesday, March 19, 2013. Atlas V will carry second Space Based Infrared System Geosynchronous Satellite (SBIRS GEO 2) to orbit. Mission Managers met on Friday to discuss the status of launch preparations and any open items that need closing before the countdown can commence. No show-stoppers were identified and the decision to go ahead with final launch preparations was made. The Launcher will be moved to Space Launch Complex 41 at Cape Canaveral Air Force Station on Monday for final launch preparations and the Launch Countdown. Two trackmobiles will be used to move the Mobile Launcher and the Atlas V with its Payload to the Launch Pad. Rollout will take approximately 30 minutes. When arriving at the Pad, the structure will be secured and electrical connections will be made. Also, propellant and communication lines will be connected. Later, the trackmobiles will be removed and pad close-outs will start to set the stage for countdown operations on Tuesday. Meteorologists are calling for a 70% chance of acceptable weather during the 40-minute launch window with Cumulus Loud Rule violations being the primary concern.

Image: United Launch Alliance

"On launch day, a cold front is expected in North Florida in the morning and pushing into Central Florida through the afternoon and evening. Moisture is sufficient for isolated showers during the afternoon and evening.," the launch forecast of the 45th Weather Squadron said. For a 24-hour delay, there is a 40% chance of uncooperative weather with high ground winds and Cumulus Clouds being the main concern.

Atlas V & SBIRS GEO 2 start final Preparations for Launch

March 8, 2013

Photo: NASA Kennedy

Atlas V Assembly - File Image

Moving along in a busy manifest of launches lined up for 2013, United Launch Alliance is preparing another Atlas V rocket for launch later this month. An Atlas V 401 is planned to launch from Cape Canaveral Air Force Station, Florida, on March 19 during a 40-minute launch window opening at 21:21 UTC. The vehicle will deliver the second Space Based Infrared System Geosynchronous Satellite (SBIRS GEO 2) to orbit for the US Military. Final preparations for this launch started on January 11 when a C-5 aircraft delivered the SBIRS GEO 2 spacecraft from its manufacturer, Lockheed Martin, to the space coast to begin final pre-launch processing. The spacecraft underwent final testing and reconfiguration tasks before being loaded with propellants and being encapsulated in the Atlas V Payload Fairing. The long fairing version is being used for this flight. Atlas V itself started its integration process at Space Launch Complex 41 on February 14. The Common Core Booster of the vehicle was moved to the Vehicle Integration Facility and installed atop the Mobile Launch Platform. The Centaur Upper Stage was transported to the Vehicle Integration Facility on February 18 and hoisted above the large first stage of the rocket. Once precisely positioned above the interstage adapter that was put in place earlier, Centaur was installed atop the CCB and electrical and data connections were made. With Centaur in position, teams started an extensive testing campaign to ensure the launch vehicle is ready to complete its mission. Testing procedures include countdown and mission simulations that allow teams to see whether onboard computers work properly and electrical systems respond as expected. With launch vehicle checkouts complete, teams were given the green light to move the payload to the launch complex. On March 7, the payload unit was transported to the integration facility, attached to a heavy-duty lifting sling, hoisted above the launch vehicle and installed atop the Centaur Upper Stage. Once electrical and data connections were put in place, the launch vehicle integration process was complete and Atlas V and its payload were ready to start a final round of integrated testing.

The pre-flight tests will include the Integrated Systems Test that puts the launcher through a full countdown and flight simulation to make sure the onboard computers of the vehicle are issuing the correct commands and all systems receive commands that are sent. The payload will complete countdown and launch procedure tests as well to confirm it is ready for its ride to orbit.

Integrated testing results will be discussed at the Launch Readiness Review that will give the final go-ahead for countdown and launch operations.

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